The vexing question of mandatory vaccines

Alongside the myriad crises Britain is currently being buffeted with, the UK is experiencing yet another one: the measles crisis. Cases of the disease in England and Wales surged beyond 1,600 in 2023 – double the number in 2019. With a measles outbreak currently plaguing the West Midlands, the UK’s Health Security Agency has officially declared a ‘national health incident’ – suggesting that case numbers could skyrocket in other parts of the country. 

So, what’s the cause? The answer is simple: fewer people are getting vaccinated. In 2022-23, 84.5% of five-year-olds had received a second dose of the ‘mumps, measles and rubella’ (MMR) jab – the lowest vaccination rate in a decade. Importantly, it’s well below the 95% threshold for measles that must be reached to achieve herd immunity: where sufficient numbers of people are vaccinated to significantly limit the spread of disease. 

A healthy person remaining unvaccinated places these groups directly in the firing line of illness

Declining vaccination rates for all forms of preventable disease are a long-running trend in the UK – driven by vaccine hesitancy and aggravated by the Covid-19 pandemic.  In response, some have argued for mandatory vaccination, where the government compels people to get jabbed and punishes them if they do not comply, whether it be through fines or denying them access to public places. Mandates implemented across Europe during the pandemic generally succeeded at increasing vaccination rates, which begs the question: should the UK take the leap and mandate vaccination? 

An obvious concern about vaccine mandates is that are fundamentally coercive, limiting the freedom and bodily autonomy of those subject to them. However, freedoms are never absolute – and infringements upon individual liberty could be justifiable given they enable the advancement of other goals – such as public health objectives. There may be strong grounds for mandates given an individual’s decision not to get vaccinated creates ‘externalities’ – outcomes of a person’s behaviour that affect those other than themselves. By refusing to get vaccinated, individuals increase the likelihood that they will get infected with disease, and therefore infect others. Moreover, they may compromise society’s ability to achieve herd immunity– further facilitating the spread of otherwise preventable illnesses. This is especially salient considering vaccination is often unsafe for groups particularly vulnerable in the event of infection – such as pregnant women and the immunocompromised. A healthy person’s decision to remain unvaccinated places these groups directly in the firing line of illness, significantly strengthening the case for restrictions on their behaviour. 

Rather than making sweeping determinations we must evaluate mandates on a case-by-case basis

That being said, it’s worth emphasising that the extent to which mandates are justified in any given case is heavily context-specific, depending on the society on which they are being imposed, alongside the nature of the disease in question and the vaccines themselves. 

Experts heavily emphasise the necessity of proportionality – mandates must be commensurate to the public health threats they seek to address. There is a significantly stronger case for mandates in situations where diseases are highly contagious, vaccines are proven to have a low risk of creating side effects, and healthcare systems are at breaking point, unable to respond to surges in cases.  

Another consideration is whether mandates are truly necessary to limit disease transmission, or whether less coercive means can get the job done. The WHO argues mandates should generally be an option of last resort, only being implemented if alternatives such as community outreach efforts are insufficiently effective. This is particularly true given their potential to generate public backlash and undermine trust in health professionals, as they did in Ukraine in the 2000s. In situations where this happens, mandates can be counterproductive, not only reducing vaccination rates, but also reducing compliance with other public health measures. It’s notable that the UK’s Covid-19 vaccine rollout was a resounding success despite the lack of a mandate – a product of robust collaboration between Whitehall, local governments, and grassroots ‘community champions’. If this strategy could be applied to vaccines for other diseases, perhaps this would limit the necessity of mandates. 

There are two primary considerations at play when assessing the case for vaccine mandates. Firstly, does the disease in question pose a sufficient threat for a mandate to be justified? Secondly, are there alternate policy options on the table that can achieve the public health objectives of mandates without the trade-offs they inevitably entail? For diseases like measles, there may be a strong case for implementing one, given the sheer contagiousness of the disease and its potentially lethal complications. However, these conclusions are not generalisable to other pathogens, and it’s imperative that, rather than making sweeping determinations, we evaluate the need for mandates on a case-by-case basis.